1. Field of the Invention
The present invention relates to a perpendicular magnetic recording medium that may be installed in a variety of magnetic recording devices, and to a fabrication method thereof.
2. Description of the Related Art
As capacities of magnetic disk recording devices have become larger, a demand for high recording densities of magnetic recording media has increased. In conventional magnetic recording methods, longitudinal magnetic recording methods predominate, but, recently, perpendicular magnetic recording methods have been attracting attention as techniques for realizing a high recording density for the magnetic recording media.
A perpendicular magnetic recording medium has, as constituent elements, a magnetic recording layer of hard magnetic material, and an under layer formed from a soft magnetic material which, fulfills a role of concentrating a magnetic flux produced by a magnetic head employed to record on the magnetic recording layer. Currently, a CoCr alloy crystalline film is principally used as the soft magnetic material used for the magnetic recording layer of the perpendicular magnetic recording medium. Tests involving the refinement of CoCr crystal grains, a reduction in a particle size distribution, and intergranular interactive control, and the like, have been performed to achieve higher densities going forward.
On the other hand, a rare earth-transition metal alloy noncrystalline film, which is employed as a material for magneto-optical recording, has a large perpendicular magnetic anisotropy constant Ku, and exhibits highly superior thermal stability. Thus, this metal alloy noncrystalline film is extremely promising as a magnetic recording layer material for the perpendicular magnetic recording medium.